Hi,

I have very poor Windows 11 VM performance in games, example Fallout 76 has only 30-50 fps and lagging badly. If I boot computer up with Windows 11, I will get over 120fps easily. But in Unraid games are unplayable.

System:

i9-14900K

MB Asus ROG STRIX Z690-A GAMING WIFI D4

64 GB RAM

VGA 24GB RTX 3090 Asus Rog Strix (tried also with RTX 3080 Ti, same problem)

In bios are VT and IOMMU enabled.

In Unraid:

IOMMU group for VGA is binded.

CPU pinning: cores 4 - 15 are isolated and pinned to VM. Cores 0-4 and 16 - 31 are pinned to dockers.

VM settings:

CPU mode: passthrough, Migratable: off

16GB RAM

Q35-9.2

USB 3.0 qemu XHCI

Primary vDisk Kingston Fury Renegade 1TB NVMe (tried also with Unassigned Devices, installed directly to Samsung 850 Evo SSD)

VGA passed through with sound controller. Using HDMI plug.

Network model: virtio

Using VM over Parsec and Moolight/Sunshine (tried also with direct attached monitor+keyboard+mouse)

Screenshot:

Before that I had system with i7-11700 CPU, it was acting much better. Sometimes there were stutters but games were generally playable.

What can I try to improve VM performance?

Example enable PCIe ACS override and pass through NVMe drive directly? Or unpin all cores and let Unraid to manage all cores?

Or something else?

I just managed to fix my problem!

I tried same fix from "Poor performance Ubisoft games" thread.

I gave from Unraid terminal a command:

sysctl -w kernel.split_lock_mitigate=0

And now games are running buttery smooth!

Hint came from here:

I was having a similar problem with Windows server 2025, everything was laggy and slow on remote desktop. With this "sysctl -w kernel.split_lock_mitigate=0" rebooted unraid & to be honest made the remote desktop much smoother to operate, a noticeable difference.